BEIRUT, Lebanon — Israel said Wednesday it had wiped out half of Hezbollah’s arsenal in a week of fighting, but the Shiite guerrilla group and some experts say that claim is wishful thinking. With supply lines disrupted and no early cease-fire in sight, the big question is how long Hezbollah can hold out.

Rockets with ranges far enough to hit cities deep inside Israel have been Hezbollah’s most potent weapon since fighting flared July 12.

Israel has said it is ready to fight Hezbollah for several more weeks, and expects it will take time to destroy the group’s arsenal.

But many experts believe Israel has little chance of eliminating the rockets entirely unless it launches a ground offensive to push the group’s rocket launchers back so they cannot reach Israel.

And a ground offensive could be costly in terms of casualties, at a time when Hezbollah chief Sheik Hassan Nasrallah has made no secret of his wish to see his guerrillas take on Israelis face-to-face.

Without a ground operation, said Israeli counterterrorism expert Boaz Ganor, “It can be assumed that they will get new rockets from Iran and Syria. I think they have room to breathe for weeks. If they get more supplies ... it can last longer.”

Disrupting supply lines not working?Israel has disrupted Hezbollah’s presumed supply lines by bombing the main highway to Syria and imposing a naval blockade on Lebanon, but some trucks are still going on back roads and smuggling is possible through mountains.

Hezbollah has long proved expert at finding ways to receive money and weapons — and hide them.

Only if Israel used “real-time intelligence from human assets on the ground” to find hiding places could it seriously limit the danger from Hezbollah’s rockets without a ground offensive, said Elias Hanna, a retired Lebanese army brigadier general.

But Hezbollah has been immune to infiltration because of its tight internal security and secrecy, said Hanna, now a military analyst.

Hezbollah also has other assets — beyond its rockets — that could help ensure its long-term survival as an effective fighting force: The religious conviction of its guerrillas, their mastery of traditional guerrilla tactics and the popular support they enjoy among Lebanon’s 1.2 million Shiites, particularly in the south.

‘Ignorant of the magnitude’Many Hezbollah fighters are seasoned soldiers with combat experience from years of fighting Israeli forces in a border strip the Jewish state occupied for 18 years. Israel, faced with mounting casualties, was forced to leave the strip in 2000, a decision that Hezbollah and many in Lebanon viewed as a major Arab victory.

Mostly drawn from the region, Hezbollah’s estimated 5,000 to 6,000 fighters can easily blend into the local population, relying on residents for food, water and shelter.

Hezbollah also is known to have mastered concealment, with much of its hardware buried underground or hidden in olive and orange groves.

“Israel’s biggest weakness is that it’s ignorant of the magnitude of Hezbollah’s resources,” said Helmi Moussa of As-Safir, a Beirut daily known to be close to Hezbollah.

“It (Hezbollah) does not have a massive force. But it’s big enough to make every step the Israeli army takes in Lebanon a very costly one.”

Israel has not specified exactly what it thinks Hezbollah has in its arsenal, or how much has been destroyed.

But overall, Israel’s army says 950 rockets fired by Hezbollah have landed in Israel since July 12. Hezbollah had in the past boasted of having 12,000 missiles.

Hezbollah is thought to have rockets, possibly manufactured in Iran, with ranges of up to about 45 miles. It also has bolstered its arsenal of assault rifles, land mines, light artillery and anti-aircraft guns with night vision equipment and aerial drones.

‘All options are open’A senior Israeli army commander, Brig. Gen. Alon Friedman, said Wednesday that airstrikes had destroyed “about 50 percent” of Hezbollah’s arsenal. He said it would take time to destroy the rest.

Army spokesman Capt. Jacob Dallal said Wednesday that Israel hit a total of 1,000 targets in eight days, about 20 percent of them Hezbollah missile launching sites, missiles and command-and-control centers.

Dallal refused to rule out the possibility of a large-scale land offensive in Lebanon, saying “all options are open.”

In his last public appearance, a televised address Sunday, Nasrallah ridiculed Israel’s assertions that the larger part of his group’s rockets has been destroyed.

“The arsenal that you fear is still there. What has been used of it is very little. And our ability to fire many, many more remains intact,” he said.